Could it be a timing issue? 2002 Ponitac Sunfire SE

My son accidently shifted from third to second instead of forth while getting on the freeway, and heard grinding, so he went to neutral, but when he pushed on the gas, nothing happened.  So he pulled over and shut off his car, and when we got there to tow it, it wouldn't start.  Towed it home and it still won't start.  You can tell it's not an alternator, or starter..... could it have jumped out-of-time?